Electric signaling-box.



A. KEMPSTON.- ELECTRIC SIGNALING BOX. APPLICATION rum) FEB. 23, 1909.

Patented Dec. 27, 1910.

i-II EEHEEQ E uaRRis PETE UNITED STATES PATENT OFFICE.

ARTHUR KEMPSTON, OF SAN FRANCISCO, CALIFORNIA.

ELECTRIC SIGNALING-BOX.

To all whom 'it may concern:

Be it known that I, ARTHUR KEMPSTON, a citizen of the United States,residing at San Francisco, in the county of San Francisco and State ofCalifornia, have invented a new and useful Electric Signaling-Box, ofwhich the following is a specification in such full and clear terms aswill enable those skilled in the art to construct and use the same.

This invention relates to a fire alarm box and its especial object is toproduce a box which will not interfere wit-h the signal being sent infrom any other box, nor will any box sending in a signal interfere withthe sending of the signal from that box when the l1ne is clear.

In general the object is accomplished by holding any box in a positionsuch that-it will start to send its signal to the main office at acertain time after any other box has completed its round of signaling,and

no matter how many boxes may be started at one time one will obtain theline before another and hold all the other boxes that may be startedtill it gets through with its signal.

In the drawings, which are partly diagrammatic, and in which the samenumeral represents the same part throughout, Figure 1 is a frontelevation of one form of fire alarm box, the wiring being shown in adiagram, Fig. 2 is a side view of the timing escapement wheel, and Fig.3 is an edge view of the timing escapement and means for retarding thestop bar, a portion of the latter being shown.

The box is provided with the front and back plates 2 and 1 to which issecured the mechanism for driving the make and break apparatus forsending the signals. The back plate 1 has a solenoid S secured to it atits upper edge within which operates a plunger 3, said plunger having arack bar 4 secured thereto. The rack bar 4 passes through a pair ofguides 5 and 6, the former of which forms the rest for the plunger whenthe solenoid is out of circuit and the bar has dropped down as low as itcan fall. This rack bar is provided with a block 7 on one side thereoffor an object to be explained later. The rack is in mesh with the cogsof the wheel 8 on a shaft 9, said wheel having a series of teeth on theside thereof,

which mesh with like teeth on the side of Specification of LettersPatent.

Application filed February 23, 1909.

Patented Dec. 2'7, 1910.

Serial No. 479,635.

the timing escapement wheel 10, which latter is secured to the shaft 9.The wheel 8 is loosely mounted on the shaft 9, but the light spring 11holds its side teeth in mesh with the side teeth of the escapement wheel10. The escapement wheel is caused to rotate slowly by means of theescapement 12 to which is secured the short pendulum 13, said pendulumbeing of any desired length as will be later explained;

. The driving mechanism of the box may be of any of the well knownforms, as for example the spring 14 having one end secured to the shaft15, the other end being secured to the post 16, a wheel 17 being alsocarried by the shaft 15. The gear 17 is in mesh with a gear 18 on ashaft 19, said gear 18 being in mesh with a gear 20 on the shaft 21 ofthe character wheel 22. The shaft 21' also carries a gear 23 in meshwith a small gear 24 on the shaft 25, said shaft being secured totheescapement wheel 26. Said escapement wheel is caused to run slowly bymeans of the escapement 27 to which is secured the pendulum 28.

Secured above the wheel 18 and in mesh therewith is a wheel 30 of thesame diameter as 18, said wheel 30 being secured to the shaft 31. Thiswheel 30 has a cam 32 on its side, said cam being adapted to push thearm 33 on the swinging bar 34 under the block 7. The bar 34 is pivotedto the back plate 1 at 35 and is held in cont-act with the cam 32 bymeans of the spring 36.

The wheel 18 has acircular cam 18 on its side in a notch of which dropsthe projection 38 on the pivoted bar 38, said bar being pivoted to thefront plate 2 at 39. This bar is provided with a lifting hook 40 at itsfree end and with a contact spring 41, a spring 42 assisting in pullingthe bar down when the wheel 18 has turned one round, the projection 38stopping the movement of the box by dropping into the detent of the cam18.

The make and break switch 43 is secured to a pivot 44 on the front ofthe plate 2, a small spring 45 pulling the switch down positively. Underthe switch is an adjusting screw 46 in a block 47, sald block beinginsulated from the plate 2. On the back of the plate 2 close under thefree end of the bar 38 is a projecting bar of insulating material 48, onwhich are secured clamps 49 and 50, said clamps having contact pointswhich the spring 41 is adapted to connect. The line inlets are shown onthe front of the plate 2 at 52 and 53.

The wiring, which is shown diagramati cally, consists of the line wire Lleading 'to the inlet block 52 and connected with the wire 55 leading tothe contact on the clamp 49, through the spring 4 1 to the contact clamp50 along the wire 56 to the line wire L. This being the normal conditionof the box when no alarm has been sent from it.

When an alarm has been sent from the box the bar 38 will be raised tothe position shown in dotted lines and the wheel 18 will begin torotate. The circuit in this case will be as follows: The line wire Lwill be connected with the solenoid, because of the breaking of thecontact at the points on the clamps 49 and 50, through the wire 57, andthe current will pass through the solenoid along the wire 58 to the makeand break screw 46, along the switch 43 to the wire 59 and back over thewire 56 to the line wire L. The result of ringing in an alarm in any boxis to start the character wheel to revolving and to energize thesolenoid S, but since the rack bar has its motion retarded by theescapement 12 it will travel upwardly very slowly, or should an alarm bein the course of transmission from any other box it will fall backinstantly since with every break in the continuity of the currentpassing over the line the solenoid S will be deenergized, and since theteeth on the side of the escapement wheel 10 will hold in one directiononly, the rack bar will fall down on the guide at any break in thecurrent. The bar will again start to rise, but every break will cause itto fall back again, and since it will fall much faster than it can riseit can never clear the cam 60 on the wheel 23, said cam being of thesame angular extent as the entire number of character teeth. The rackbar positively stops the sending mechanism when the cam 60 contactstherewith. Should there be no other box sending in an alarm the rack barwill continue to rise as fast as the escapement 12 will permit it tomove, and as soon as the bar is high enough to clear the cam 60 thecontinued sending of a signal from the given box will be assured, sincethe rack bar can then drop no lower than the stop 7 and arm 33 willpermit. In order to insure the continued action of the given box shouldan interruption come into the line from any cause the cam 32 on thewheel 30 is arranged to push out the bar 34 which will catch the rackbar and prevent it from falling during the time the given box has theline. It will be noted that the character wheel turns four times whilethe wheels 18 and 30 turn once, it will therefore be evident that thebar 34 will move into the position to support the rack bar when thecharacter wheel is 011 its last half turn. The

object of this device is to insure the con 'tinued movement of thisgiven box before it would be possible for any other box to start intooperation, since the time of travel of another rack :bar would be muchlonger than the time of travel of the one supported by the bar 34:.

It will be clear that it will be possible to vary the time of travel ofthe rack bar, as well as to vary the length of the cam 60, and thelength of the rack bar in the diflerent boxes in such a manner as toinsure their all operating at different times after they have beenstarted, and even if two boxes should be rung at such a time as to droptheir rack bars at the same instant they would not again operate in thesame manner since the time constant of each box is substantiallydifferent from each other, and the length of the cam on the wheel 23 isa variable quantity for each wheel.

It is to be noted that the essential feature of this invention lies inthe absolute stoppage of the clockwork mechanism until the line iscleared of signals for such a length of time as will permit the liftingof the rack bar out of contact with the cam 60 on the wheel 23, and.also in the stoppage of the box in such a position as to enable it tomake its signal in the usual manner as soon as the line is clear of allother signals for the required length of time for the rack bar to clearthe cam 60.

It is to be noted that a possible interruption of the current might takeplace during the period of passage of the character w'heel cam 60 on thelower side of the shaft carrying said wheel, but that in any box sendingin a'signal the bar can drop no farther than the stop on the arm 34. Itwill be also noted that no matter how many boxes may be rung at the.same instant, one

will obtain the line first, or if they are rung at such a time as todrop their bars at the same instant, that the following movement of therack bars will be in such an interval of time as to give one box theline before the other in which case the box obtaining the line willcontinue sending its signal without interruption from the other boxes onthe line, and all other boxes will be in the ready position as soon asthe line is clear of signals desire to telegraph a message he may do so.The reason of this lies in the fact that he can interrupt the circuit asoften as he wishes, and can interrupt the circuit during the time thecam 60 is on the lower side of its shaft, when the bar will drop andstop the box having the line, then since the time interval in sendingtelegraphic signals by hand is very short bet-ween the several impulsessent along the line the box having the line cannot get its rack barclear to continue sending its signal till the person desiring the use ofthe line for telegraphic purposes is through. As soon as he stops theuse of the line for a short time interval the box will raise its rackbar to the clear and will continue the sending of its signal to the endof its complete set of signals. It is also to be noted that in this artit is common to have the character wheel repeat its signal four times,this being accomplished in the box shown by having the wheel 18 fourtimes as large as the wheel 20 which is driven by it.

Although particular reference has been made inthis specification to mydevice as a fire alarm box, I wish it understood that I do not confineits operation to fire alarm circuits, nor my claims to fire alarm boxes,but desire to include electric signaling boxes in general.

Having thus described my invention what I claim as new and desiretosecure by Letters Patent of the United States is as follows:

1. In an electric signaling box, an electric circuit, a signalingmechanism, means to drive said mechanism, a solenoid, a plunger operatedby said solenoid and having a projection adapted to obstruct the motionof the signaling mechanism if the line is in use, means to permit thefree action of the plunger in one direction, and means to cause its slowoperation in the opposite direction.

2. In an electric signaling box, an electric circuit, a signalingmechanism, means to drive said mechanism, a slowly movable plungeradapted to obstruct the motion of the signaling mechanism if the line isin use, a solenoid for moving said plunger in one direction, means topermit the instant return of said plunger in the opposite direction ifthe line comes into use during its slow movement, and means to cut thesolenoid out of circuit during the time the box is not in use.

3. In an electric signaling box, an electric circuit, av signalingmechanism, means to drive said mechanism, a slowly movable plungeradapted to obstruct the motion of the signaling mechanism if a signal isbeing sent over the line, a solenoid for moving said plunger in onedirection, means to permit the instant return of the plunger if the linecomes into use during its slow movement, means to stop the movement ofthe signaling mechanism at the end of a predetermined number of signals,and means to cut the solenoid out of the circuit at the end of thesignaling period.

4. In an electric signaling box, an electric circuit, a signalingmechanism, means to drive said mechanism, a slowly movable plungeradapted to hold the signaling mechanism in a position ready to send asignal at the first moment the line is clear of other signals, means toreturn the plunger to its initial position instantly if the line isoperated during the period of initial movement of the plunger and beforethe signal has been started from that box, means to stop the mechanism,a solenoid for moving said plunger, and means to cut the solenoid out ofcircuit at the end of the set of signals.

In an electric signaling box, an electric circuit, a signalingmechanism, means to drive said mechanism, means to prevent the sendingof the signal for a period of time after the ringing in of the signal,means'to stop the box in said period if other signals are passing overthe line, means to permit the use of the line for sending other signalsduring the period of signaling from the given box, and means whereby thebox will complete its set of signals when the line is free from outsidesignals.

In testimony whereof I have set my hand this 13th day of February A. D.1909, in the presence of the two subscribed witnesses.

ARTHUR KEMP STON.

ll itnesses WV. T. Hsss, G. P. GRIFFIN.

